JP2008074538A - Non-contact carrying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems of a non-contact carrying device floating and carrying articles to be carried with fluid by using ultrasound waves as power, in which a large quantity of static electricity of friction electricity generated by friction among the fluid, the articles to be carried, and a device part so that dust in the air electrically charged together with the fluid is adhered to the articles to be carried, and in which there is a possibility that the articles to be carried are brought into contact with a vibrating body by lowering or fluctuation in sound wave radiation waves when receiving disturbance caused by the electrostatic charge, and thereby reliability in stability of flotage is low. <P>SOLUTION: By a module including ceramic and a storage chamber for preventing static electricity, constant blowing pressure of fluid is maintained to suppress generation of static electricity, and blowing, stop, and a flow rate are controlled along with movement of the articles to be carried to suppress the generation of static electricity to the minimum. Particularly, if a porous board of ceramic is a porous type and made from alumina material, the generation of static electricity is suppressed to the minimum. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention is capable of completely charging various transported products such as a flat glass display such as a mother glass substrate for a flat panel display and a semiconductor wafer, a glass plate, and a semiconductor loading substrate, which are easily charged and easily broken. The present invention relates to a non-contact conveying apparatus that conveys and moves a conveyed product using ultrasonic waves as power while floating in a non-contact state.

In recent years, with an increase in the number of production of flat panel displays typified by liquid crystal displays and plasma displays, the size of mother glass substrates used for these displays is rapidly increasing. This is to make it possible to chamfer as many display panels as possible from a single mother glass substrate, thereby reducing the unit price per display. However, the mother glass substrate, as a flat panel raw material for precise and precise displays, dislikes slight damage and the generation of stress as well as minute damage. It becomes difficult.

For example, in the case of transport rollers and forklifts that have been widely used as a means for transporting mother glass substrates, it is necessary to increase the number of rollers and the number of forks in order to warm up the stress applied to the substrate as the substrate becomes larger However, adjustment operations and maintenance management to precisely align the height of many rollers and forks are very laborious, and it was impossible to transport in a highly precise state. .

Therefore, in recent years, the substrate is floated by air blowing pressure with a method of floating the substrate with air (Patent Documents 1, 2, 3, and 4), and both ends of the substrate are supported by feed rollers and conveyed. Method (Patent Document 5), a method of transporting a substrate erected on a movable part while keeping it in a non-contact state by electrostatic attraction (Patent Document 6), and a slightly inclined vertical glass substrate at the lower edge A method of supporting on a support roller and carrying the upper side of the glass substrate in a non-contact state through a gas film while supporting the carrier (Patent Document 7), when vibrating a vibrating body ultrasonically A method (Patent Document 8) or the like has been proposed in which a conveyed product is levitated on the surface of the vibrating body by the radiation pressure of a sound wave, and the conveyed product is sent in a predetermined direction in a non-contact state.
Japanese Patent Application No. 2004-260801 Japanese Patent Application No. 2004-260801 Japanese Patent Application No. 2005-212954 JP-A-6-40598 Patent Publication 2003-300618 JP-A-10-271862 Patent Publication 2002-308422 JP-A-7-24415

However, in the conventional method in which the air is floated by the air pressure and transported by the feed roller, the substrate is inevitably damaged due to contact with the feed roller. Further, in the conventional transport method that keeps the substrate in a non-contact state by electrostatic attraction force or gas film, the lower peripheral edge is supported by the movable part or the support roller even if the plate surface of the substrate is non-contact. The problem of generation of contaminating particles due to the contact of the bearing part cannot be fundamentally solved. Since levitation due to electrostatic attraction force is structurally unstable, a control system for stabilization is indispensable, resulting in high equipment costs.

On the other hand, in the conventional conveyance method in which the conveyed product is conveyed by the radiation pressure of the sound wave generated by the ultrasonic vibration of the vibrating body described above, the load capacity and the support rigidity for levitation of the conveyed product by the acoustic wave radiation pressure are the fluid pressure or electrostatic suction. Since it is more than an order of magnitude smaller than levitation due to force, etc., it is highly sensitive to disturbance (robustness), and the conveyed product comes into contact with the vibrating body due to the decrease or fluctuation of the sound wave emitted when the disturbance is caused for some reason. There was a problem that there was concern and poor reliability.

In view of the above-mentioned situation, the present invention can transport various articles such as a flat glass display mother glass substrate and a flat article such as a semiconductor wafer completely non-contacting and maintaining a high clarification state. In addition, an object of the present invention is to provide a non-contact transfer apparatus that has a large additional capacity for levitation, is excellent in reliability as a transfer means, easily controls transfer speed and direction, and has a high degree of design freedom.

Therefore, the non-contact transfer device has many problems in practical use in recent years. An apparatus that floats a conveyed product with fluid air and performs non-contact conveyance is being put into practical use.
This is because the frictional resistance can be almost eliminated by floating the conveyed product when using ultrasonic waves or the like which are the power of non-contact conveyance. In the levitation device, since the conveyed product is levitated by air, a large amount of static electricity is generated due to friction between the air and the conveyed product. This static electricity is a fluid to be ejected, for example, air is charged to a potential of several thousand volts to tens of thousands of volts, so that even a small amount of floating dust is charged, and dust in the air adheres to the glass substrate of the transported product. Therefore, the meaning of precious non-contact conveyance for the purpose of maintaining a high degree of clarity has disappeared.
In addition, it is necessary to prevent the generation of static electricity in a substrate on which a semiconductor chip or the like that is normally operated at 3 to 5 volts is mounted.
In order to prevent this kind of failure in static electricity generation, grounding, temperature control, and humidity control have been implemented. However, in non-contact transfer devices that use fluid levitation, the amount of static electricity generation is large and countermeasures are awaited. It was.

In addition, the performance of the non-contact conveyance device is easily influenced by the diameter and number of holes arranged on the conveyance path, that is, the holes through which the air is ejected. The floating state of the conveyed product was influenced by the state of the hole, the diameter of the hole, and the density of the hole in a certain portion. In addition, a large amount of money was spent on processing to precisely drill holes with a suitable diameter in the part material on the floor portion on the conveyance path. Therefore, a means for solving this problem has been demanded.

In order to eject air from the floor portion on the conveyance path for moving the conveyed product, a considerably large air source is required. In addition, a large mother glass substrate or the like is required for transporting a large mother glass substrate. As described in the above-mentioned patent document, the equipment of the air source becomes huge, and the levitation force is not stable, so that the practical application thereof is possible. It was difficult.

Further, when the air source is made large, the sound of air from the jet outlet becomes loud, causing workability to be deteriorated, and causing the problem of generation of air waves of the compressor.

In order to suppress the generation of static electricity, means using a storage room is used.

By means of a non-contact conveying device that conveys a conveyed product while being levitated by a fluid without generating static electricity using ultrasonic waves as power.

In order to prevent and remove static electricity, a ceramic plate having a large number of holes as a filter, a fluid storage chamber, and means for minimizing the generation of static electricity are provided.

By means of a combination of a ceramic porous plate for prevention and removal of static electricity, a fluid storage chamber and the fluid supply means, the means for minimizing the generation of static electricity.

By means of a porous type ceramic plate made of an alumina material and ejecting fluid air.

By means of suppressing the generation of static electricity from the air ejected by the ceramic, and discharging the charged fluid air into the air so as not to give static electricity to the dust in the air.

The floor portion on the conveyance path is a module including a ceramic plate and a fluid storage chamber, and the fluid is ejected from the surface of the ceramic plate provided in the installed module.

Further, in order to change the direction of the conveyed product, the module uses a corner portion that changes the direction of the conveyed product.

By means of detecting the movement of the conveyed product with an optical sensor and sequentially controlling the ejection of the fluid from the previous module by the control means for controlling the ejection, stop and flow rate increase of the fluid with the movement of the conveyed product.

When the power to be conveyed is a small amount of energy such as ultrasonic waves, it is necessary to minimize the effects of static levitation and static electricity. The prevention of noise due to electrostatic discharge and the like were able to achieve these purposes as shown by the effects of the above means.

Adopting a fluid storage chamber that is divided into multiple and continuously combined, it is easy to control the pressure of the fluid ejected from the surface of the ceramic porous plate, and the air ejection pressure can be kept uniform and stabilized .

In other words, the transported product is a module in which the surface of the perforated ceramic plate or ceramic porous plate is smooth and constant in height and does not cause an error in the direction specified by the ultrasonic wave, and the transported product stably and smoothly hits the floor portion. It can move while floating on the ceramic porous plate.

By adopting a storage chamber, the inflowing fluid does not directly collide with the transported object, and not only diffuses the fluid into the storage chamber and keeps the air pressure constant, but also there is a storage chamber, so air and pipes that guide that air, etc. The generation of static electricity due to friction with the wall of the wall can be eliminated and suppressed.

By making the air pressure constant, the generation of noise from the ceramic porous plate during the squeezing out was reduced.

By using a ceramic plate with a hole or a porous ceramic plate at the air outlet, static electricity can be prevented from being generated due to friction between the fluid and each hole in the ceramic porous plate, and the static electricity can be eliminated. I can do it now.
The ceramic porous plate functions as a filter for removing static electricity.

By using a porous porous ceramic plate and an alumina material, it is possible to obtain a uniform pore distribution, a uniform pore size, and a low pressure loss in the porous plate. Therefore, it is possible to obtain a uniform levitation force due to the ejection of fluid.

When the porous ceramic plate is porous and uses an alumina material, there is less charge to the fluid due to the uniformity of the pore distribution and the uniformity of the size of the pores, and the static electricity due to the charge due to friction between the transported product and the fluid and the fluid. Can be minimized.

By using ceramic porous type and alumina, the generation of static electricity is minimized, and the conveyed product comes into contact with the vibrating body due to the decrease or fluctuation of the sound wave when subjected to disturbance for some reason. The reliability of the equipment has been improved without doing so.

It can now be used to transport substrates loaded with semiconductor chips that are sensitive to static electricity, such as glass that is easily charged.

Since the charge of fluid such as air is small, it is difficult to charge the dust floating in the air, so that the dust floating in the static air does not adhere to the conveyed product.
In particular, dust adheres less to easily charged glass.

With the module divided into a plurality of modules, the degree of freedom of the combination of modules in the direction of the conveyance path is improved. The length of the transport path has become easier.

At the corner, the direction of the conveyed product can be changed by a fan-shaped module.

Since the ceramic plate can be divided together with the storage chamber, there is no need for a long ceramic plate or a porous ceramic plate, and there is an advantage that the plate is inexpensive.

Control means for controlling the ejection of the fluid from the surface of the porous or perforated ceramic plate along with the movement of the conveyed product sequentially activates the ejection of the fluid in the storage chamber along with the movement of the conveyed product to place the conveyed product. Since it is necessary to supply fluid only to the module part at the moving position, there is no ejection of fluid in the part of the storage room where there is no need for levitation of transported goods, so that generation of static electricity can be minimized. It became like.

Therefore, a large air source for levitating the conveyed product is not required, and the air source can be performed with a small size.

Therefore, since the air source has become smaller, the occurrence of air waves in the compressor has been eliminated.

The purpose of non-contact conveyance can be achieved by detecting the position of the conveyed product using light in the fluid ejection control means.
The movement of the conveyed product is detected by an optical sensor, and the fluid ejection from the module is sequentially operated by the control means for controlling the fluid amount with the movement of the conveyed product. Static electricity can be kept to a minimum by friction with air.

In order to prevent the generation of static electricity of the fluid in the conveyance device that propels the conveyance product with ultrasonic power, the part where the fluid is ejected uses a ceramic plate as a filter and is modularized with the fluid storage chamber to reduce the generation of static electricity. Therefore, the ejection of the fluid is sequentially performed, and the ejection of the fluid is controlled together with the movement of the conveyed product.

The non-contact transfer device is composed of an ultrasonic unit and a transfer unit using fluid levitation.
The ultrasonic unit is a drive unit or the like that generates a slight force for moving and transporting the lifted transported product along the transport path direction. As a method of driving, various methods such as a method described in the above-mentioned patent document, an ultrasonic wave, a sound pressure, static electricity, and the like are considered. An outline of a drive unit that is an actuator that generates a driving force for conveyance according to the present invention will be described. As an example, the actuator used in (Japanese Patent Application No. 2004-260801) can be used. Conveyed goods floating on the conveyance path are transported in a specified direction by the acoustic viscous flow generated between the elastic diaphragm arranged along the conveyance path and the surface of the conveyance article facing the elastic diaphragm. Like to do. The product is moved with a slight force applied to the product.
The lifted transported product is moved along the transport path direction.

Hereinafter, the characteristics of the configuration of the non-contact conveyance fluid levitation apparatus of the present invention will be described. This device is a conveying device that uses ultrasonic power to propel the conveyed product. In order to prevent and eliminate static electricity, a ceramic plate with a large number of holes or a porous ceramic plate in the processing and manufacturing process, and a fluid The substrate or the charged object transported by the fluid supply means and the fluid supply means, wherein the fluid is ejected upward through the perforated ceramic plate and the semiconductor electronic chip is loaded upward by the ejection pressure. It is characterized by being transported while levitating. The ceramic porous plate is porous and made of an alumina material.

This apparatus is characterized in that a ceramic plate for preventing and removing static electricity and a fluid storage chamber are formed as one module, and the module is a fan-shaped or arc-shaped corner portion that changes the direction of a conveyed product. Yes.

This device detects the movement of the conveyed product with an optical sensor, and controls the flow of the fluid in the upward direction of the module by the control means for controlling the ejection of the fluid along with the movement of the conveyed product. It is characterized by things.

FIG. 1 shows the principle of operation of a non-contact conveying fluid pressure levitation device according to the present invention.
For the sake of explanation, the ultrasonic wave generation portion is not shown.

In FIG. 1, air 6 is ejected from a storage chamber 3 through a ceramic plate 2 and ejected from a surface 7 of the ceramic plate.
Each module 11 is supplied with fluid air in a thin tube 4 branched from the thick tube 4.
The tube 4 is connected to each module 11 by a joint 5.
The light transmitter 13 and the light receiver 14 of the non-contact sensor are provided at the beginning and end of the transport path 1.
Therefore, unlike the second embodiment, the first embodiment cannot control the ejection of fluid for each module.
The ceramic plate 2 attached to the module 11 may be made of a porous material or may be one having holes 12 formed therein. The air 6 is ejected from the surface 7 of the ceramic plate at a relatively uniform and constant pressure, and the conveyed product 8 placed on the ceramic plate 2 is levitated upward by the pressure of the fluid and moves in the conveying direction 9. .

Due to the length of the ceramic plate 2, the distance between the ceramic plates 2, the mass of the conveyed product 8, and the levitation pressure due to the fluid, the clearance created between the bottom surface of the conveyed product 8 and the ceramic surface of the module 11 is increased. In order to keep it constant, it must be designed with the buoyancy pressure of the fluid.

FIG. 2 shows a second embodiment. Unlike the first embodiment, the modules 11 are continuously arranged in the conveyance path 1 without providing a fixed interval.
The control means for jetting, stopping, and increasing / decreasing the air 6 detects the position of the conveyed product 8 by the light transmitter 13 and the light receiver 14 of the non-contact sensor, and feeds the air 6 through the tube 4 to operate the solenoid valve 10. To control the movement of the fluid. A tube 4 is connected from the solenoid valve 10 to each module 11 by a joint 5 to the module 11. Further, in order to make the ejection pressure of each module 11 constant, a pressure control valve may be used for each module 11. The apparatus of the part of the fluid pressure levitation | floating of the non-contact conveyance which can be made to blow, stop, and increase / decrease the air 6 to the module 11 with the movement of the conveyance article 8 is represented.

  The contactless sensor is not limited to light transmission / reception, and may be ultrasonic or infrared, and may be of any type as long as it is contactless.

In Example 2, the positions of the light transmitter 13 and the light receiver 14 of the optical sensor are arranged on the left and right of each module 11, and the presence / absence and position of the conveyed product are detected. The sensor may be disposed on the ceramic surface 7 of the module 11.

In the transfer device for propelling the transfer article 8 by using ultrasonic power, a rectangular shape is formed of a fluid storage chamber 3 that is divided into a plurality of portions and arranged continuously, and a ceramic plate 2 that ejects fluid to the upper portion of the storage chamber 3. Modules 11 are arranged continuously.
The present embodiment is a conveying device that propels a conveyed product by using ultrasonic power as a power source, and an ultrasonic wave generation unit 17 attached to a stand 16 is disposed at an appropriate interval from the surface of the module.
The ultrasonic wave generated from the ultrasonic wave generation unit 17 acts on the conveyed product 8, and the conveyed product 8 moves in the conveying direction 9.

In the first and second embodiments, the same modules 11 having the same outer size are used side by side. However, it is also possible to achieve the object of the present invention by using several modules having different shapes in sequence. It shall be included in the range.

FIG. 3 is an enlarged cross-sectional view of the module 11 shown in FIGS. Modules 11 having ceramic plates 2 and storage chambers 3 arranged on the conveyance path 1 at respective intervals are linearly arranged at regular intervals along the conveyance path 1.
A storage chamber 3 for storing air 6 is provided below the ceramic plate 2. Air 6 as a fluid is sent into the storage chamber 3 from an air supply source such as a compressor through a tube 4 and a joint 5. You may circulate and use the air 6 in a clean room. Further, instead of the air 6, another gas such as nitrogen may be used as the fluid.

A space is provided in the wall surface of the storage chamber 3 so that the fluid 6 supplied through the tube 4 does not directly collide. The tube 4 is connected to the storage chamber 3 by a joint 5.

An ultrasonic generator 17 is disposed on and attached to the stand 16.
The conveyed product 8 is levitated by the fluid ejected from the hole 12 on the surface 7 of the ceramic plate 2 and moves by obtaining a propulsive force without contacting the surface of the ultrasonic wave generating portion 17.

FIG. 4 shows a corner portion of a device of a fluid pressure levitation portion for contactless conveyance. A fan-shaped or trapezoidal corner module 15 is provided.
Each part name, configuration, and combination are the same as in FIG.

Example 1 of the non-contact conveyance device of the present invention is shown. Example 2 of the non-contact conveying apparatus of the present invention is shown. 2 shows a module with a ceramic plate and a storage chamber. The corner part of Example 1, 2 is shown.

Explanation of symbols

1. 1. Transport path 2. Ceramic plate Storage room 4. Tube 5. Joint 6. Air (fluid)
7). 7. Surface of ceramic plate Conveyed goods9. Transport direction10. Solenoid valve 11. Module 12. Hole 13. Optical sensor light transmitter 14. Optical sensor light receiving unit 15. Corner module 16. Stand 17. Ultrasonic generator

Claims (8)

In a transfer device for propelling a transfer product using ultrasonic waves as a motive power, the hole is formed by a ceramic plate having a large number of holes for preventing and removing static electricity, a fluid storage chamber, and the fluid supply means. A non-contact conveying device that ejects fluid upward through a vacant ceramic plate and conveys the conveyed product upward by the ejection pressure. In a conveying apparatus for propelling a conveyed product using ultrasonic waves as a motive power, a porous ceramic plate for preventing and removing static electricity, a fluid storage chamber, and the fluid supply means include the ceramic porous plate. A non-contact conveying device that ejects fluid upward and conveys the conveyed product in the upward direction by the ejection pressure. 3. The non-contact conveying apparatus according to claim 2, wherein the ceramic porous plate is a porous type and made of an alumina material. 3. The non-contact conveying apparatus according to claim 1, wherein the non-contact conveying apparatus is used for conveying a charged body. 3. The non-contact transfer apparatus according to claim 1, wherein the non-contact transfer apparatus is used for transferring a substrate on which a semiconductor electronic chip is loaded. 3. The non-contact transfer apparatus according to claim 1, wherein a ceramic plate for preventing and removing static electricity and a fluid storage chamber are formed as one module. The non-contact conveying apparatus according to claim 1, wherein the module is an arcuate corner portion that changes a direction of a conveyed product. The movement of the conveyed product is detected by an optical sensor, and the flow rate of the fluid is sequentially ejected, stopped, and increased / decreased by the control means that controls the ejection of the fluid together with the movement of the conveyed product. The non-contact conveyance apparatus of Claim 6 and Claim 7.

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